Isspro EV pyro inaccurate

[daveg]

Those who have the new Isspro EV pyro may want to check the accuracy. I replaced my Isspro 607G series with the EV series because of lighting. I immediately noticed a higher EGT reading at specific speeds. I took both gauges to my supplier,Oregon Fuel Injection, for testing on their master. The EV actually showed a 50 degree lower reading all the way to 1500 degrees. The master does not use a probe, but sends a signal to the gauge. After returning home, and still being suspicious, I hooked another lead wire to my probe and ran it into the cab so I could observe both gauges at the same time. Confirming my suspision, the EV showed 150 degrees higher at 1200 than the 607G.



To cure the problem, my supplier contacted Isspro, whose rep. advised how to remove the cover from the amplifier box (which has a "warrantee void if removed" sticker on it) and adjust the proper potentiometer for correction.



The pyro now follows the 607G all the way to 1200 degrees. I really like the looks and lighting of these new gauges, especially with green bulb condoms.



I don't know why the master tester and road reality were different, but I am sure Isspro and suppliers will work it out.



Sorry for the long post but this is how it went.

 

[PRout]

This is very interesting because ive been questioning my EV ever since i put it in. It seems to read high.



At cruise it runs 750 w/ only 4-5 lbs boost (not even working hard), and I can easily run 1300 at half throttle pulling a load up a grade in high gear. Still have lots of power left, but have been afraid to use it. I ran it up to 1350 once and felt like it could get to 1400 easily, maybe more.



Hmmm...

 

[DLBurns]

Does this apply to the EV marine gauges

I just got my Isspro EV Marine gauges... am I going to have to recalibrate the amplifier also

As they are not installed yet, I'm inclined to send them back and have Isspro make it right!

 

[daveg]

The adjustment in the amplifier box is simple but you need a 2nd lead wire and a known good 607G to calibrate it to. Also, since I did mine with the knowledge of Isspro, my warrantee is still intact.

 

[Brent - DIS]

I have talked to Isspro on the issue and they have told us the following.



In this situation where Isspro has you go into the amplifier to make an adjustment based on the service bulletin they put out you WILL NOT void you warranty.



We have a tester here and are making this 1/2 turn on all our stock and they are coming out with a correct temperature. The reason the R600 tester is mentioned is this Service Bulletin was written for dealers/installers.



If you are not comfortable making this modification simply call us/or the isspro dealer you purchased from (make sure they have made the modification) and will swap out your pyrometer.



Here are some scan of the Service Bulletin and how to perform the fix.



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Brent

DIS

 

[PRout]

To be fair, I can not say mine is inaccurate, because I have not compared it to a known-good one. This thread just seemed to go along w/ a suspicion, and thats all. No facts yet.



It might be spot on. According to the recent TDR mag, they found that their EV was basically right in there with the others.



I really like the EV gauges. Just hope they are accurate from the factory w/o having to recalibrate them.



Time will tell.



Edited: Thank you DIS for the above post. I hadnt caught your post before making this comment.

 

[DAWG-1]

Isspro EV adjustment

I used the tester on my EV gauge yesterday 01-03-02 and found the my pyro was close to a 100* higher than actual. I removed the cover and made the adjustment. The gauge and tester does not read the same temp and that is the problem, for example the meter is set 975* and the gauge is to display 900* per Isspro directions. Sam

 

[redneckdr]

EGT

my new isspro ev, i think is high also. this from comparing notes with another tdr member on temps at comparable speeds. he has SPA gauge, and mine reads 100-150* higher at comparable speeds. i'll have to use the UUFF (Uraneous Universal Fudge Factor). i guess it's safer to have it a bit high, than a bit low... .

 

[JohnE]

For those of you doing the adjustment, make sure to use <em><b>Low Odor</b> RTV</em> for setting the trim pot and resealing the amp cover. The conventional RTV you use on gaskets or the diffy cover is very corrosive to electronics.



my 2 reale (bits)

-John

 

[illflem]

John, no more reales, just Eurodollars since 1/1.



RTV sealant is used far too much by backyard mechanics. I can't begin to count how many poor running gassers I've had to scrape the stuff off. The fumes mess with the electronic sniffers in smog systems.

 

[R.E. Miller]

I thought mine was reading funny too

I bought my EV's because I figured that the Isspro product would be the most accurate Something else to fix

Russell

 

[JohnE]

Bill;

My 2 reale silver cob went out of circulation in the late 1500's.



Don't believe the label when it says <em>sensor safe</em>. The low odor types such as GE RTV 6700 Series is the better product.



R. E. , et al;

I feel ISSPro makes a very high quality product. I've been waiting around 18 months for the &quot;EV&quot; Series.

I used to work in the electronic industry and while one hopes to get it perfect the first time these things do happen on new product lines.



-John

 

[PRout]

Well, if the TDR mag's article on gauge comparisons is correct. We could devise a . 026 volt source to calibrate our gauges to 1200 degrees. That would be good enough.



Could be a crude setup w/ a aa batt & a couple resistors for a voltage divider for that matter. A variable supply, or whatever works. As long as we have a decent multimeter to make sure were at the right voltage while we make the adjustment.



It would be cool to hook it up as close to the sensor as possible to calibrate the system (which would comphensate for loss from the long leadwire). Ok here we go. . whats the easiest source for . 026 v, hmmmm.



Also, we used hot glue on ckt boards at Motorola, and a rubber spray treatment.

 

[redneckdr]

isspro ev egt

talked to doug at ADT lat night. i got my gauges from him. he said he had discussed this with Isspro--was assured that they had recalibrated a number of the gauges, and the correection is 1/2 turncounterclockwise . this apparently is very constant, and should correct the high reading. i asked about the waranty, and doug assured me that my warranty will still be intact. i think you should contact your source before attempting the correction, to be sure you are covered. doug offered to recalibrate mine if i sent it back, but i'd rather do it my self, than try to get it out of the truck

 

[BLACKRAM]

I also had a problem with the EV accuracy. My first pyro was the Isspro. After switching to the EV series (for better lighting), I noticed 150-200 higher degree temps. A few phone calls to Isspro later, they insisted the gauge was accurate. Did that mean I was cooking my pistons with the previous gauges?



Thanks to this post, and the TDR I now have an easy fix.

 

[SlyBones]

Well I just dont get it.



1. Used to a given reading at a given speed , on the existing 607 gauge.

2. INstall EV and start seeing higher readings

3. Have them tested, the EV is 50* low.

4. Reinstall and run tests.

5. At same load, 607 reads 1200* and EV 1350* ( 150 higher )



-- Insert my observation based on how I read that information. The real reading is 1400*, the EV is 50* low and the 607 is 200* low.



6. Now calibrate the EV to match the 607.



-- Isnt it now worse??



What did I miss??

 

[SlyBones]

I was just observing in the last week that I think my current Isspro 607T gauge is reading low.



About 2-3 weeks ago a given section of I-5 at a given speed was about 900*, now its 600*. -- I can also be crusing down the freeway at 70, and see 350*, punch it, run up to 85 or so and only see 500*. -- I think its broke.

 

[PRout]

These gauges are quality. Just need to get them calibrated right.



After suspecting mine was reading high, I went ahead and turned it down half a turn on the trimmer as per the doc.



Im just a little leary that its too low now, because I can get down to 300 in about 20 seconds after stopping. After about 2 minutes it can be darn near down to 250, maybe 265. Does this sound right?? Cruise at 65 @ 4 lbs boost shows 550-600*. Most people seem to report about 650 at this speed.



I tried making a 26mv source from a battery & a bunch of resistors, but at that value of resistors I used, it couldnt hold the voltage when connected.



So, guess its time to run down to the electronics supply & get the parts to make a hard source (like the one in the TDR mag). Should be able to set it right on for 1200* Just have to find some time.



Not giving up on these gauges though. This'll be worked out.

 

[PRout]

Ok, Game's over on mine.



Heres the deal (in case there's one person thats actually interested in this).



Couldn't stand to look at the thing thinking its unreliable. So, looked at the schemo in the TDR mag. Well, the article was excellent, but the schematic seems to have a misprint.



Depending on how you interpret the vertical line running through the opamp to negative, you either have a directly shorted input supply (in which case - poof), or you have a 12 volt output that bypasses everything (wouldnt be too good to hook that up to the gauge - IMO).



So, somehow I was able to play with the ckt, bypassing the opamp part, and it actually works (powered by an old 9. 6v makita batt). Got a supply that has all the voltages you would want to dial it in at any temp.



Set it at 26mv (. 026v) (oh, using the fluke 87 by the way, still has the broken probes, heehee, but good equipment). Hooked it up (after already performing the Isspro mod which is turning the pot half turn counter clockwise).



Ill be darned... It read 1225 degrees! Exactly what they got in the mag. Id say that the factory re-adjustment appears to be very close. At 13mv it reads 660* (should be 600). I figure it was about 65* outside, so that makes it seem about right (if im thinking correctly - someone please correct me if im wrong). Also at 19. 5mv it was 940* (should be 900). Factor in air temp, and it seems reasonable.



The method used was: I removed the probe (sender) from the ckt first. Connected the tester to those leads which seems like id be calibrating the thing to be accurate w/ the super long leadwire. Actually, Im a little confused about if I should turn it up to comphensate for outside temp, or factor in the leadwire, but thats how I did it. Again, tested it w/ the long leadwire in the ckt.



So, the half-turn adjustment DIS advised seems to be right on.



Thank you DIS, and I sure do love my beautiful Isspro EV gauges. Have already had a few comments on the quality appearance too.

 

[JHansen]

Thanks for the info Shortshift. I emailed Isspro yesterday and got a return e-mail from Kelly today with her phone #-I'll call her Monday and see what the story is-but I feel a lot better about making the adjustment now.



Jason